Ecodan hits 300 per cent efficiency over worst winter for decades

A live trial of an Ecodan air source heat pump in Hertfordshire has demonstrated that the system was still achieving over 300 per cent efficiency levels (a COP of 3.0 – Coefficient of Performance) throughout the whole of last December, when the country faced long periods of sub-zero temperatures not seen for decades.

The trial has not only shown that air source heat pumps will work effectively in British homes under such harsh conditions, it also highlights the importance of sizing and selecting the radiators and heat emitters properly and ensuring that the homeowners know how to get the best out of the system.

The 1950’s, 4-bedroomed house in Berkhamsted, is the home of a family of four with two children aged 15 and 12.  The homeowner had new high-tech Jaga radiators fitted when the Ecodan system was installed in the autumn of 2010 and the whole system has since been closely monitored by Mitsubishi Electric.

During December, while the whole of the country felt the full force of the harshest winter weather for years, the family enjoyed an average` indoor temperature of around 20°C, keeping them warm and comfortable throughout the entire Christmas period. 

“The key to these high efficiency levels is keeping the flow temperature around the system low,” explains Jason Tinsley, Technical Manager for Ecodan.  “During the icy month of December, the average flow temperature was only 33°C, yet the family remained perfectly warm.”

Another important element in the success of this system was the choice of Jaga’s Strada DBE radiators, with their Dynamic Boost Effect allowing the homeowner to increase a room’s temperature quickly if necessary, with the radiators providing maximum heat emission for around 15 minutes to help unheated rooms reach the desired temperature.

Modern radiators, such as the Strada DBE offer maximum efficiency at low water temperatures and also contain around 15 per cent of the water normally held in a traditional radiator.  This means that there is less water in the entire system that needs to be heated before the effects are felt within the room and allows the Strada DBE to deliver the heat needed more quickly.

“Intelligent radiators like these use microprocessors to monitor the surrounding conditions in ways that traditional ones simply can’t and they will react to outdoor temperatures much more quickly, reducing the heat output if necessary or raising or lowering the flow temperature as required,” adds Tinsley.  “This gives the homeowner much better control of the overall energy use.

“Although none of us enjoyed the prolonged icy weather in December, we are delighted that it gave us the chance to clearly demonstrate how well Ecodan can perform,” he added.

The 8.5kW Ecodan unit, which is installed in the alleyway of the house, has been monitored over the last six months and provides all the heating and hot water that the family of four required.  In addition to domestic hot water it feeds nine Jaga Strada DBE radiators throughout the home.

With some manufacturers now claiming COPs of 4.0 or even 5.0 (5kW of heating from every 1kW of electrical energy consumed by the heat pump) Tinsley is urging anyone considering a heat pump to remember that these COPs will typically have been measured in laboratory conditions at an outdoor temperature of 7°C (or higher) with the unit supplying a water flow at a temperature of 35°C, or even lower.

“What we recommend looking at instead is the ‘Seasonal Performance’ of a heat pump, to get a full understanding of how the system will work in a complete range of temperatures and operating conditions across the year.  All credible manufacturers should be able to supply this information,” he ends.

Further details on Ecodan are available by emailing heating@meuk.mee.com, or visiting the website www.mitsubishielectric.co.uk/domesticheating. Details on the advanced range of Jaga radiators are available at www.jaga.co.uk.

Mitsubishi Electric

Mitsubishi Electric’s award-winning, Ecodan® air source heat pump is specifically designed for the UK and straightforward to install. The quiet,…